Faecal microbiota transplantation with anti-inflammatory diet (FMT-AID) followed by anti-inflammatory diet alone is effective in inducing and maintaining remission over 1 year in mild to moderate ulcerative colitis: a randomised controlled trial.

Objective: Microbiome and dietary manipulation therapies are being explored for treating ulcerative colitis (UC). We aimed to examine the efficacy of multidonor faecal microbiota transplantation (FMT) and anti-inflammatory diet in inducing remission followed by long-term maintenance with anti-inflammatory diet in patients with mild-moderate UC.

Design: This open-labelled randomised controlled trial (RCT) randomised patients with mild-moderate (Simple Clinical Colitis Activity Index (SCCAI) 3-9) endoscopically active UC (Ulcerative Colitis Endoscopic Index of Severity (UCEIS)>1) on stable baseline medications in 1:1 ratio to FMT and anti-inflammatory diet (FMT-AID) versus optimised standard medical therapy (SMT). The FMT-AID arm received seven weekly colonoscopic infusions of freshly prepared FMT from multiple rural donors(weeks 0-6) with anti-inflammatory diet. Baseline medications were optimised in the SMT arm. Clinical responders (decline in SCCAI3) at 8 weeks in both arms were followed until 48 weeks on baseline medications (with anti-inflammatory diet in the FMT-AID arm). Primary outcome measures were clinical response and deep remission (clinical-SCCAI <2; and endoscopic-UCEIS <1) at 8 weeks, and deep remission and steroid-free clinical remission at 48 weeks.

Results: Of the 113 patients screened, 73 were randomised, and 66 were included in (35-FMT-AID; 31-SMT) modified intention-to-treat analysis (age-35.7±11.1 years; male-60.1%; disease duration-48 (IQR 24-84) months; pancolitis-34.8%; SCCAI-6 (IQR 5-7); UCEIS-4 (IQR 3-5)). Baseline characteristics were comparable. FMT-AID was superior to SMT in inducing clinical response (23/35 (65.7%) vs 11/31 (35.5%), p=0.01, OR 3.5 (95% CI 1.3 to 9.6)), remission (21/35 (60%) vs 10/31 (32.3%), p=0.02, OR 3.2 (95% CI 1.1 to 8.7)) and deep remission (12/33 (36.4%) vs 2/23 (8.7%), p=0.03, OR 6.0 (95% CI 1.2 to 30.2)) at 8 weeks. Anti-inflammatory diet was superior to SMT in maintaining deep remission until 48 weeks (6/24 (25%) vs 0/27, p=0.007).

Conclusion: Multidonor FMT with anti-inflammatory diet effectively induced deep remission in mild-moderate UC which was sustained with anti-inflammatory diet over 1 year.

Trial Registration Number: ISRCTN15475780.